LiFEPO4 battery installation orientation, does it matter? To me no.

[Zucca]

I am planning to build my 16S battery pack with EVE LF280K.
I would like to make two horizontal 8s strings laying on long side one on top the other, with terminals on the side (not on the top).

I am surprised to find so much discussion on this topic:

https://diysolarforum.com/threads/eve-lf280k-orientation.47128/

https://diysolarforum.com/threads/lifepo4-on-its-side.5215/

To me the installation orientation does not matter in a LiFEPO4.
I even asked the EVE representative and in poor English it looks like the orientation does not play a role, as long the insulation between the cells is preserved.

If know more than me in this please write a line below....

TIA!

[james_s]

No, it makes no difference, they can be operated in any position. The only cells that are sensitive to orientation are flooded cells, mostly lead-acid, but flooded NiCD also exist.

[Honusnap]

It's wrong??? they can't be stored or used on their large sides.. nor upside down.
Only posibilities : Vertically, vent on the top or on their small side.
There is still some electrolyte in those ... check for EVE last PDF, they specify expressly NOT to store/use them on the large side.

[ejeffrey]

The LiFePO4 cells can be operated in any orientation.  The "vents" are only emergency overpressure safety valves.  The cells are sealed under normal operation and won't leak or care about orientation.

The only possible concern is physical forces in a multi cell battery. The housing of primatic cells is thin and not particularly strong.  Depending on the pack construction it's possible that the wrong orientation would put pressure on some cells.  So do follow the manufacturers directions. Most manufacturers say they can be oriented on any direction, but if yours says otherwise you should follow that.

[Siwastaja]

The idea of correct orientation originates from manufacturers. I remember Winston/Thundersky actually instructing that the cells must not be oriented up side down. Whether that really makes any difference is a different question. Maybe it was just one more Winston Chung's diversion, a way for them to explain away cell failures. Maybe orientation actually correlated with failures, root cause of course being in crap quality.

[indeterminate]

Wound flat cells , that is any lifepo4 cell in a rectangular container can suffer from swelling and should be clamped between end plated to stop this from happening.

The plates are clamped / welded to the bottom of the terminals in an air gap between the wound section of the cell and the top of the case
if you orientate  the terminals at the bottom it is possible that the wound plates can slide in the case and short out against the terminals.

Laying them on the long side you end up with the bottom cell being crushed and insufficient clamping force on the top cells.

The battery in the photo has been running the house for over 10 years now, note the clamping system